The use of bridging beams to reinstate poles used by utilities for carrying communications lines, electric power lines and the like has become an effective means for extending the lifetime of damaged, rotted or weakened poles. Whilst bridging beams have specifically been used to reinstate poles used by utilities, it is to be appreciated that this technique has application to other forms of poles including pylons, stumps, flagpoles, warning posts and the like and as such, the invention also has application in these alternative situations.
Bridging beams have particular application to wooden poles. It is well known that a wooden pole is most vulnerable to rot, decay or similar degradation at about ground level including the area from slightly above to slightly below the ground line of the standing poles. This is the area in which rot generally begins and as the decay spreads, the pole is weakened. If a utility pole should fail, there may be serious disruption to telecommunications and/or power supply. Further, the sudden failure of a pole is a risk which linesman working on such poles face regularly. In addition to the risks of a faulty pole falling and bringing down not only the lines but also the linesman with it, there are risks to passersby and neighbouring buildings or other structures. Similar dangers and inconvenience may result from the failure of poles used in other applications.
Thus, the reinstatement of damaged poles is an important consideration. However, it can be difficult to properly identify damage to a pole. Accordingly it may sometimes be necessary or advisable to provide added strength to a sound pole. The terms reinstate and reinstatement are accordingly used herein to refer to the addition of strength to a pole irrespective of whether the pole has been previously damaged and/or weakened in any way.
Typically, a pole may be reinstated by securing a bridging beam to the surface of a pole over the region where it is rotted or weakened. The bridging beam may be securely attached by drilling holes diametrically through the pole and securing the bridging beam to the pole by bolts extending completely through the material of the pole. Where a pole is particularly weakened, two or even more bridging beams may be applied in this fashion.
Whilst such approaches have met with a degree of success, the fact that holes need to be drilled through the hole diameter means that the actual wood or other material comprising the pole is further weakened by virtue of the removal of material through drilling. Clearly this is one aspect of the process which is directly contrary to achieving the desired object.
To some extent, the problems caused by weakening the pole through drilling holes may be overcome by using a stronger bridging beam or using multiple bridging beams. However, as the use of stronger or multiple bridging beams inevitably leads to increased costs, it would be preferable to be able to use a weaker bridging beam if the integrity of the pole can be retained by avoiding the use of holes drilled completely through the pole.
It would also be advantageous to be able to provide a basic bridging beam design which can be reinforced to increase its strength.
This invention seeks to provide bridging beam designs and/or methods of installing bridging beams which may be of assistance in meeting one or more of the desirable aspects of bridging beams discussed above.